MQTT And Azure IoT

For more information on these topics, see MQTT Protocol and Introduction to Microsoft IoT Hub.

System Requirements

The requirements for a successful configuration are listed below.

• MQTT Driver version 0.2.1
• Microsoft Azure IoT Hub Account
• Visual Studio Code with an Azure IoT Hub

Configuration Settings

In this section, we will describe how to configure each program.

Visual Studio Code

Visual Studio Code is an open-source, streamlined code editor with support for development operations like debugging, task running, and version control. Visual Studio Code can be downloaded here.

To download the extension that allows interactions with Azure IoT Hub and IoT Device Management, click here.

After installing the extension, open the VSCode application. In the explorer pane of the VS Code, click the ”Azure IoT Hub” tab in the bottom left corner (1 below) and click ”Select IoT Hub” (2) in the context menu.

If you are not signed into Azure, a pop-up will appear in the bottom right corner to prompt you sign in to Azure (3).

Your Azure Subscription list will appear after you sign in. Select the Azure Subscription and IoT Hub. After a few seconds, devices and endpoints will appear in the Azure IoT Hub tab. 

New IoT Devices can be created through this extension. Select the context menu (1 below), click on Create Device (2), and enter a Device ID for the new IoT device. 

Now that your device is created, you need to setup your Connection String and SAS Token. 

To do this, right click on your device and select Get Device info. You should see information displayed in the output window. 

Review the Connection String that was created for the device and make note of the following pieces of information from this string:

HostName = TatsoftTestHub.azure-devices.net DeviceId = NewDevice

Again, right-click the device and select ”Generate SAS token for device” and enter the expiration time. You should see some information displayed at the Output Window.

Record the following pieces of information from this string:

Password = SharedAccessSignature sr=TatsoftTestHub.azure-devices.net&sig=pzzXCZK%2 BQ6dJUe2Hf1SptTR1oPMbfyip0K9M4TQPZc4%3D&skn=iothubowner&se=1593008673

To verify that data is flowing from MQTT Driver to the cloud-based Azure IoT Hub, right-click the device entry and select ”Start Monitoring Built-In Event Endpoint”.

MQTT Driver

On your Project’s Engineering Environment, navigate to Devices > Channels and add a new MQTT channel.

On Devices > Nodes, add a node for the newly created MQTT Channel. The Primary Station configuration is done as follows:

URL = <Host Name> Port = <Port Number>
Client ID = <Device Id>
Username = <Host Name>/<Device Id> Password = <SAS Token>
TLS Version = <TLSv1.0>
X059 Certificate = <Certificate thumbprint>  (optional)  QoS = <Quality of Service>
Keep Alive = <Message sent to Broker to prevent the link from being broken> (in seconds)

For our IoT Hub and Device configured in VSCode, the parameters are as follows.

URL = TatsoftTestHub.azure-devices.net Port = 8883
Client ID = NewDevice
Username = TatsoftTestHub.azure-devices.net/NewDevice
Password = SharedAccessSignature sr=TatsoftTestHub.azure-devices.net&sig=pzzXCZK%2 BQ6dJUe2Hf1SptTR1oPMbfyip0K9M4TQPZc4%3D&skn=iothubowner&se=1593008673

TLS Version = <TLSv1.0> X059 Certificate =
QoS = AtMostOnce Keep Alive = 1

Lastly, on Devices > Points the Address information is filled according to the syntax below

devices/<Device Id>/messages/events/

For our device, the correct topic is

devices/NewDevice/messages/events/

Once the Device configuration is complete, go to Run > Startup and execute the project. Open the Trace Window (with Debug and Devices options enabled) and monitor the communication exchange.

Back on VSCode, you can see the received messages on the Output Window.